Li-Ion Battery Costs Challenge Engineers on EV Safety

The dark cloud hanging over electric vehicles in the wake of recent Chevy Volt fires may not lift, no matter how much engineers to do improve EV safety. That's because they're up against the gating factor of battery pack cost.

Experts say rising concerns over safety are going to make it tougher for engineers to dramatically cut the costs of lithium-ion battery packs. Already, General Motors is reportedly considering a redesign of its lithium-ion battery pack to help prevent damage during a collision.

"We just don't know how much lower we can go in terms of price," says Donald Sadoway, a battery expert and the John F. Elliott Professor of Materials Chemistry at Massachusetts Institute of Technology. "It's not as if we can stand on the shoulders of all the work that's been done on cellphone and laptop batteries up to now. Laptop batteries don't have to be crashworthy."

The National Highway Traffic Safety Administration said one Volt fire occurred after a side crash test was performed on it in May. During the test, the vehicle's battery was damaged, and a coolant line was ruptured. The fire occurred three weeks later. Three similar tests in November did not result in fires, though one damaged battery did emit sparks and smoke, the agency said.

Experts are confident that current cooling systems, coupled with improved crashworthiness, will keep electric cars safe. "We will learn how to better deal with the safety issues," says Elton Cairns, a professor of chemical and biomolecular engineering at the University of California-Berkeley and a designer of fuel cells for the Gemini spacecraft program during the 1960s. "After all, any battery that can fit on a vehicle stores much less energy than a tank of gas."

Still, the concern is that lithium-ion batteries are already too costly, and that new safety measures will prevent them from dropping significantly in cost, even as economies of scale kick in. Today about half of the cost of an EV battery pack lies in its "non-cell" portion, according to the National Research Council, and that number could go up if crashworthiness becomes a big issue.

Kind of a sobering post, Chuck, but very enlightening. Based on what you outlined, it seems likely that refining Li-ion batteries and cooling system designs are likely only to deliver incremental benefits in terms of lowering costs--not nearly enough to move the bar in terms of sparking sales. As far as developing alternatives to Li-ion batteries, that seems like a long way off. It would be a shame to lose ground given how far we've come in the last five years in terms of wannabe acceptance of the EV as a mainstream vehicle.

The plethora of ongoing engineering challenges with electric vehicles -- specifically, the cost of batteries (as discussed in this article) and their apparent vulnerability to fires) -- makes me wonder why fuel-cell vehicles are completely off the table. Only two years ago, Honda and several other automakers demoed hydrogen fuel-cell cars at major auto shows. These are ready to go; the big impediment is a complete lack of infrastructure. I still don't get why these vehicles have been ignored. It's a workable, safe technology. Maybe the word "hydrogen" scares people.

There's no doubt that the word "hydrogen" has a fear factor associated with it. But experts have pointed to additional issues with hydrogen fuel cells. At a recent UBM-sponsored panel discussion at the Embedded Systems Conference, experts cited three issues with fuel cells: outgassing, storage and infrastructure. But I think much of the problem comes down to this: In a sense, we've all been spoiled. Gasoline-burning cars are marvelous machines and they've raised our expectations so high that it's difficult for any new technology to come in and match up. Automakers are now tasked with satisfying incredibly high consumer expectations. If they don't build reliable machines, they'll be rightfully flooded with complaints from people who've invested $30K or $40K in their shiny new vehicles.

I agree, Beth, that it would be a shame to lose the momentum that the EV market has gained in the past five years. In the long run, though, I think the momentum won't be completely lost. I believe we'll see that momentum swing to hybrids and plug-in hybrids, which can use smaller lithium-ion batteries that inherently cost less. If we're going to continue publicly pushing pure EVs, it might be better for us to direct our efforts toward battery research. I don't believe we'll ever see a battery that can compete with the energy and cost characteristics of gasoline in our lifetimes, but if we could create a battery that could meet the old $100/kWh target, it would go a long way toward bringing pure EVs to the masses.

@Alexander Wolfe: The days of throwing huge sums of money at fuel cell research pretty much ended with the Bush Administration. Besides the issues which Charles cites, there is the larger issue of where to get hydrogen from. It may be the most abundant element in the universe, but here on earth, it's mostly tied up in water and hydrocarbons. If you want to separate the hydrogen from these compounds, you need to put energy in. Where do you get that energy from?

At best, hydrogen is an energy storage medium, not an energy source. And as an energy storage medium, its energy density is much less than that of batteries.

You're absolutely correct that most of the safety concerns about hydrogen are unfounded. However, that doesn't mean the technology makes sense.

I did some work on hydrogen fuel cell technology for the Department of Energy as an undergraduate. It was very interesting from a materials engineering point of view -- and it was inspiring to feel like I was helping to lay the groundwork for an energy revolution which would someday break our dependence on carbon-based fuels. However, the more I learned, the more skeptical I became that hydrogen will ever be either environmentally sustainable or economically viable.

A couple years later, I worked briefly for a professor who was building a hydrogen-powered lawnmower as a demonstration project for a major city's parks department. He kicked me off the project after I asked too many "big picture" questions which he couldn't answer.

Good comments, Dave. Interesting how promising technology changes when you move it from the lab and into production. In your case, I guess it didn't look like promising technology even when it was in the lab.

I agree, Rob. Battery technologies have been notorious for looking good in the lab but not as good in production. I started covering electric cars in '88, and back then every battery looked great in the lab. Virtually every battery maker promised to bring vehicle range up to 300 miles and cost down to $100/kWh. One academic said that it was like being in "a liar's contest. Whoever told the biggest whopper got the most money." But for two decade now, these technologies have never quite realized their promise when they leave the lab.

As I sit alone, late at night hiding behind my pseudonym and reading about batteries and safety, a couple of thoughts cross mind.

1. What are the NH-TSAs doing? Do they just look at dents and crash dummy damage? I would expect that they [if they were a company in the private sector] would perform some level of 'autopsy' after a crash test - especially if it involved a 'not very common technology' like battery power.

2. 'Instant gratification types' and 'academians' are always whining about the lack of infrastructure when something a little different might come to market. That would be nice and make for quick adoption, but it is contrary to the mass deployment of any new product that comes to mind. What was the infrastructure when the first automobiles were being sold? Or when the first mobile phones and cable TV service were sold in the 1940s?

mellowfellow, I agree with your statement in regards to the NHTSA post testing procedure. In the event that I had a crash that totalled the rear end of my car and it was leaking gasoline, I would surely immediately have the tank repaired or removed to stop the potential fire hazzard. I would not wait three weeks without doing anything.

Mellow, the problem of early adoption does not seem the same now as it was then.

Take light bulbs. The Edison Screw is by far the most widely accepted. Even new CFL bulbs are using this century old design. There were competing designs (and still are), but the lead early adopter pushed his design into the de-facto standard.

Gasoline nozzles are the same way. Petroleum companies early on saw the BENEFIT of commonality; they could push more of their product if all vehicles had the same receptacle.

Today, there's not many instances where an innovator make such a leap that nearly everyone sees the benefit of following the de-facto standard. Companies see an opportunity to create their own "standard" hoping more people will follow them than the competition. VHS vs. Betamax, Blu-Ray vs. HD-DVD are good examples where competition caused early adoption grief.

Consumer battery sizes (AA, AAA, C, D) are all over a century old, though the sizes were formally ratified as ANSI standards in the USA in the 40s and 50s.

It's not a matter of "something a little different". If producers would be willing to standardize even a little bit, the infrastructure problems would be much less.

A few weeks ago, Ford Motor Co. quietly announced that it was rolling out a new wrinkle to the powerful safety feature called stability control, adding even more lifesaving potential to a technology that has already been very successful.

A well-known automotive consultant who did an extensive teardown of BMW’s i3 all-electric car said its design is groundbreaking in multiple ways. “We’ve torn down about 450 cars, and we’ve never analyzed anything like this before.”

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